Windshield wiper blade



Feb. l2, 1963 Filed Oct. 24, 1958 J. w. ANDERSON 3,076,993

WINDSHIELD WIPER BLADE 2 Sheets-Sheet 1 (Kim INVENTOR JOHN W. A NDERsoNBY/a'f. MMM A Q0. 711C 1J, c. S. P 'f ATTORNEYS Feb, 12, 1963 J. w.ANDERSON 3,076,993

WINDSHIELD wIPER BLADE Filed oct. 24, 195e 2 Sheets-Sheet 2 YzNvmTok.JOHN W. ANDERSON :SY/12W Q ggg 7241?,

TORNEVS United States Patent Gtice B Patented Feb. l2, li

envases YVINDSHEELD lil/EPEE? BLADE John W. Anderson, 57S Broadway,Gary, Antl. Filed Get. 2d, i958, hier. No. 769,404 i3 (Claims. (Cl. .l5-256.4%

This invention relates to a windshield wiper assembly and moreparticularly to an improved wiper assembly for wiping dat, curved, and/or wrap-around Windshields and to an improved method of making same.

An object of the invention is to provide simple means by which therelative ilexibility of various longitudinal portions of a flexiblebacking strip for a wiper for curved windshields may be varied toconform to varying curvaitures of the windshield.

A further object of the invention is to provide a method by which aportion of the ileXor, or backing strip, of a wiper blade tor curvedwindshields, may be increased in effective length and in flexibilitywithout substantially increasing the over-all length of materialrequired to produce the flexor, or backing strip, thus to attain greateriiexibility in said portion for more ready and more extended response towiper arm pressures transmitted thereto.

A further object of the invention is to provide a method of manufacturewhereby the ilexibility of a predetermined portion of a flertor, orbacking strip, may be changed by forming such portion so as to increaseits effective length i i e at the same time changing the thickness ofthe material in said portion, whereby to alter the resistance of thetlexor, or backing strip, to flexing under pressure transmitted theretofrom the wiper arm.

Another obiect of the invention is to provide a flexor, or backingstrip, in which the flexibility oi dierent portions thereof is reducedor increased respectively to provide a combination of longitudinal andtransverse deformations of the material from which sai-d strip is made.

A further object of the invention is to provide means by whichvariations in the degree of conformability ci different longitudinalportions of a wiper blade, in maintaining contact of said blade,throughout its length, with la windshield surface of varying degrees ofcurvature, may be accomplished without the employment of auxiliarysprings or of members iniluenced thereby.

A further object of the invention is to facilitate conformity of a wiperblade to varying degrees of curvature of a surface to be wiped withoutsubstantially varying the width of the ilexor, or backing strip,throughout its length.

A further object of the invention is to provide a flexor, or backingstrip, for wiper blades for nonflat windshields in which both linear andtransverse deviations in the shape of the material used may be eiectedeconomically in a single forming operation.

A further object of the invention is to provide an improved wiper blade,a portion of which, adjacent an eX- tremity thereof, conforms readily tocomparatively abrupt curvatures in the outwardly extending portions ofthe surface to be wiped.

A still further object of this invention is to provide a wiper assemblythat is suiliciently flexible to conform to the surface being wiped andis sufficiently inflexible in portions thereof to prevent such portions:from lifting from the windshield, particularly under the influence ofwind currents and the like.

And yet another object of this invention is to provide an improved wiperassembly of simple construction and operation, which is not only moreeconomical to manufacture, but also is etlicient in use.

Other objects and advantages of the invention will become evident afterconsidering the description hereinafter set forth in conjunction withthe drawings annexed hereto.

In the drawings:

FIGURE l is a side View in elevation of a preferred form of my improvedwindshield wiper blade assembly as applied to a windshield;

FIGURE 2 is an enlarged view of the right-hand portion of the fullassembly of FIGURE. l removed from the windshield;

FLJURE 3 is a bottom view of the backing strip or iiexor of FiGURE ltogether with the underengaging sliding claws at the ends of thepressure-transmitting means;

FIGURE 4 is a side view of the ilexor of FIGURE 3;

FIGURE 5 is a cross-sectional view taken along the line 5--5 of FGURE 2;

FGURE 6 is a partial cross-sectional View taken along the line 6 6 ofFIGURE 2;

FlGURE 7 is a side view of a modified form of my irnproved windshieldwiper blade assembly;

FiF-,URE 8 an enlarged view of the right-hand portion of the fullassembly of FIGURE 7;

FEGURE 9 is a bottom view of the backing strip or flexor of FGURE 7together with the underengaging sliding claws at the ends of thepressure-transmitting means;

FlGURE l0 is a side view of the iiexor of FIGURE 9;

FEGURE ll is a cross-sectional view taken along the line l--ll of FEGURE8;

FEGURE l2 is a cross-sectional view taken along the line l?, l2 ofFEGURE 8; and

FlGUlE i3 is a cross-sectional view taken along the line 13a-i3 ofFlGURE 8.

Referring more particularly to FIGURES l-6 of the drawings, thewindshield wiper assembly is generally designated lil and is comprisedof a wiper blade ll and a pressure-distributing device l2. The wiperblade l1 is comprised of an elongate resiliently tlexible support,backing, or fleXor T13 and a resilient rubberlike wiping element ldcarried by the support. The pressure-distributing or transmitting devicel2 may be constructed in various ways, but as herein illustratedpreferably includes a pair of corresponding secondary yokes l5 and 16having their ends slidably connected to the blade l1, a primary yoke 17having its ends connected to intermediate portions of the secondaryyokes, and a connector 1S carried by the primary yoke for connectionwith the end portion of a windshield wiper arm i9.

The fleXor i3, as will be described in detail hereinafter, is elongateand has corresponding end portions 2l and 22 and an intermediate portion23 of a greater width than the end portions. This variation in widthforms shoulders which provide longitudinally spaced abutment means 2,5and 2.6. The support or llexor 13 is preferably provided with anelongate narrow slot 28 terminating short of the ends of the support toprovide connecting or hinge portions 29 whereby longitudinal parallelside portions 30, 31 of the support can be spread apart to enlarge thesize of the slot so that the resilient element 14 can properly belocated therein, after which the longitudinal portions 3i), 31 arereleased to cause such portions to interlock with the element ld. Due tothe character of the support or flexor, the blade is primarily limitedto ilexation or movement in a direction substantially perpendicular to asurface of the windshield to be cleaned.

The wiping element 14 is provided with. an attaching or back portion 32and a wiping portion 33 which is joined to the attaching portion by anintermediate restricted portion or web 34 so as to permit tilting of thewiping portion. The attaching portion is provided with a pair ofcorresponding grooves 35, one being located adjacent each side of theattaching portion in a predetermined position so that they liesubstantially in the same plane. The grooves 35 receive theinterrnarginal edge portions of the longitudinally extending portions30, 3l of the support El for holding the support or flexor is andelement llt assembled.

The secondary yokes and lid are preferably identical in design andconstruction. The inner end of the base wall of each secondary yoke isformed to provide a transverse arcuate or curved end and a pair ofcorresponding ears or claws 37. The outer end of each secondary yoke isprovided with a shroudlike end wall 38 which serves to conceal the endsof the support. The outer end of each of the secondary yokes l5, i6 isalso provided with a pair of ears or claws 39 spaced inwardly from theend wall 38. When assembled with the blade, the pairs of ears or claws37 and 39 of the yoke l5 extend over the reduced extremity 2l of thesupport or flexor 13 and 'the corresponding ears or claws 37 and 39 ofthe yoke 16 similarly extend over the extremity 22 of the support orilexor to effect a sliding feature between the yokes and the support.rThe secondary yokes 1S and Elo are preferably assembled with thesupport by merely sliding the yokes inwardly along the extremities ofthe support until the inner ends of the yokes engage the abutment means,after Which the primary yoke 17 is attached to the secondary yokes in amanner shown and described in my copending application Serial No.609,633., filed September 13, 1956, now Patent No. 2,955,3l3.

It is to be understood that the invention is not intended to be limitedto the above-described pressure-transmitting `system or to theparticular shouldered ilexor, these elements being shown and describedfor illustration pun poses only.

The flexible support or flexor i3 is provided with a means wherebydifferent degrees of flexibility are introduced into the fiexor duringmanufacture of the exor to satisfy the particular wiping requirements ofthe blade assembly with which the lieXor is to be used. rthat is, on awindshield with an extreme curvature, particularly on the outboard sideportion thereof, it is necessary for the wiper blade 11 comprising thewiping element 1.4% and the ilexor 13, lying substantially beneath theoutwardmost secondary yoke 16, to flex or bend in the plane lyingsubstantially perpendicular to the surface of the Windshield to a muchgreater extent than for older type curved windshields. By providing theiiexor 13 with a more freely exible portion in the area where greaterand more severe flexing isY required and by maintaining the balance ofthe fiexor or support with a lesser degree of flexibility, a wiper bladeis produced that conforms throughout its length to more sharply curvedsurfaces of a windshield, such as are encountered in wrap-around typewindshields.

In one preferred form, such as shown in FlGURES 1-6, inclusive, theone-piece ilexor iff is shown with the claws 37, 39 of each secondaryyoke l5, le embracing the `edge portions ofthe reduced end portions 2l,Z2, respectively, of the exor. The end portion 22 of the eXor 13 hascorrugations 42 formed therein in a direction lying substantiallyperpendicular to the longitudinal axis of the flexor 13 throughoutsubstantially the length of said reduced end portion 22. Thecorrugations ft2, in the preferred showing, are preferably of a waveformation having substantially straight, parallel, regular, and equal-vly curved ridges 43 and valleys 4d, as best shown in FG- URES 2 and 4.The corrugations 42 caribe produced during the forming of the flexor andhave the effect of reducing the resistance of the end portion 222V toexing, which has a greater range of adaptability to purposes deynedherein than does reducing either the widthor the thickness of thematerial of which the lexor is made.

As referred to above, fleXor 13 may be made from a piece of material ofsubstantially uniform standard thickness normal for a particular wiperassembly. The transverse corrugations 42 herein proposed are addedsimultaneously to each side portion 3i?, 3l throughout substantially thelength of the end portion 22 of the tiener so as to preferably terminatejust short of the inner claws 37 and outer claws 39 of the secondary`yoke il@ when i sembled with the pressure-transmitting device 12. The resulting exor 13 has the usual degree of flexibility throughout theuncorrugated portion of the liexor and has a substantially increaseddegree of flexibility throughout the corrugated end portion Z2 of thetlexor.

The incorporation of the corrugations 4,2 into the ilexor has the effectof increasing the effective length of thel ilexor Without substantiallyincreasing or decreasing the actual length thereof. In one preferredmethod of form ing the corrugations into the tiexor, two matching corrugated dies, equal in length to the desired length of the corrugatedportion of the flexor, are simultaneously' forced together against theinterposed end portion of the.` ilexor. increments of the end portion ofthe exor areI simultaneously stretched and bent between the dies to*thereby form successive ridges and valleys resulting inv the corrugatedshape. 'the stretching of the metal of the end portion adds effectivelength to the liexor, but due to the bending into the corrugated shapethe actual length of the flexor remains substantially the same.Simultaneously, the stretching of the metal of the corrugated portionalso reduces the thickness of the metal in the corrugated portion bycomparison to the uncorrugated portion or portions of the flexor. r[heresult of both the increase in the effective length and the reduction inthe thickness of the said end portion of the flexor is to substantiallyincrease the flexibility of said corrugated end portion of the iiexor.

The corrugated end portion 22;, beneath the secondary yoke i5, istherefore more flexible in a direction substantially perpendicular tothe plane of the exor and, when assembled with the rubber element of ablade, results in a blade having different degrees of flexibility atprede ermined portions along its length to meet the demands to be placedupon the wiper assembly with which the exor is to be used.

Since the corrugations i2 may be formed simultaneous-4 ly by the samestroke of the press that cuts or forms other parts of the exor, as thematerial is fed progressively into the press, the corrugating operationadds no cost to the production of the flexor. Thus, the ilexor embodiedin the present invention produces a substantially improved result whenincorporated in a wiper assembly without in any way increasing the costof producing the flexor. Likewise, an improved reiill assembly of thetype described and claimed in U.S. Patent No. 2,782,445 results from theincorporation in said rell of the inventive concept above described.

Maximum curvatures of the windshield encountered by the wiper assemblylll are those traversed by the outer end portion of the blade, wherereduced resistance to iiexure, occurring under the outer secondary yoke,assists the blade to conform to the surface of the windshieid beingwiped, The surface area of the glass traversed by the mid-portion of theblade, i.e., that portion lying between. the respective inner claws 37,37 of the secondary yokes'y l5, lo, is usually less abruptly curved and,therefore, yless llexibility in the iexor is required. The mid-portion.of the blade wipes the somewhat more critical area'of the-v windshielddirectly in the line of vision of the driver and is the portionordinarily more susceptibie to lifting oif' the glass through pressureof air currents encountered against the windshield indriving. it hasbeen found that by maintaining, in that portion or segment of theiiexor:

each end of each relatively more flexible portion are normal,predetermined pressures that substantiaily insure satisfactoryconformity of the wiping edge of the rubber element to the windshieldthroughout the entire length of that element and throughout the entirestroke of the blade.

it will be understood that when the iiexor (as has been practicedheretofore) is of the same thickness throughout its length the need forgreater iiexibility to cause the "lade to conform to the sharper outercurvatures of a wrap-around Windshield might force a decision to adopt auniform thickness ot the iiexor, generaliy too thin to hold the middleportion of the rubber rmly enough to the glass to prevent windlift andchatter of the blade at higher car speeds. Thus, it may be seen that nouniformly desirable compromise in exor thickness as between theseextremes has been readily attainable in the art. ri`he presentinvention, however, permits any desired diierential in flexibility ofany predetermined longitudinal portions of the iiexor, to promoteconformity and prevent mid lift of the blade, without adding to the costof producing the blade.

Most windshields currently in use and projected for future use havesurface portions in the vicinity or the wiper shaft which aresubstantially flat or are only moderately curved so that one end portionof the blade assembly need not be any more iiexible than the centralportion of the blade. The one preferred form shown in FIGURES l to 6 isof the type just described, namely, one end portion Zi is inherentlymore tiexible than the mid-portion 23 of the iiexor and blade. The otherend portion Z2 of the flexor is corrugated at 5.12 to increase theflexibility thereof so that the blade in the vicinity of thecorrugations more readily conforms to the sharp wrap-around curvaturesof the windshield.

ln the windshield wiper replacement market, there are a 1:arge number ofwiper blades sold that may be installed on a wiper arm as readily withone end or" the blade outward as with the other end outward. it is,therefore, desirabie to provide, under each secondary yoke, the sameexibility since it is impractical to rely upon servicemen or car ownersto select one or the other end of the blade to install in the outboardposition. Accordingly, it is to be understood to be within the scope ofthis invention to have corrugations ft2 at either end portion, at bothend portions, or at any larger or smaller increment of the length of theblade to arrive at any desired result with respect to varying degrees ofiiexibility throughout the length of the blade.

in my copending application Serial No. 710,598, ed January 23, 1958, nowabandoned, l have disclosed a way to increase the resistance of portionsof a iieXor to flexing in a particular plane by adding longitu inallydisposed. channels or ribs in the sides or the ilexors. The channelsserve as stifiening members so as to decrease the tienibility of theportions receiving the channels. it is to be understood to be includedwithin the scope or this invention to incorporate transversecorrugations in a portion or portions of a exor to increase theexibiiity of that portion or portions of the llexor and also toincorporate longitudinal channels in another portion or portions of theeXor to reduce the flexibility of that portion or portions of theiiexor.

FGURES 7-13 illustrate a modified form of my invention wherein a wiperassembly Si) comprises a wiper blade 5l and a pressure-transmittingdevice 52. The wiper blade 5l is comprised of an elongate exible supportor ilexor 54 and a resilient rubberlike wiping element 55 carried by thesupport. The illustrated pressure-transmitting device 52 is comprised ofa pair of secondary yokes 57, 53 and a primary yoke 59 connected to theintermediate portions of the yolzes 57, 53. A connector 6b` is carriedby the primary yoke for attaching the wiper assembly to a windshieldwiper arm.

The wiping element 55' is provided with an attaching portion e2 and awiping portion 63 which is joined to the attaching portion by a web ditso as to permit tilting, of the wiping portion relative to the attachingportion. The attaching portion 62 is provided with a pair ofcorresponding grooves 66, one being located in each side of theattaching portion in a predetermined position so that they liesubstantially in the same plane. Near each end of each groove 6e in theattaching portion 62 of the element 5S is an abutment 67 extendingtransverse to the base of the groove whereby the ends of the grooves areclosed. Grooves 66, with the ends closed as at 7, are sometimes referredto as blind grooves or pockets.

FGURES 9 and l() illustrate the modified form of lexor 54 adopting theteaching ot` my invention to a two-piece type ilexor. The lienor .f5-thas two unattached independent sides 7i, 72 each with corresponding endportions 73, '74 and an intermediate portion 7S delineated from the endportions by abutment surfaces 77, 7S formed in one edge of each side 71,72. rEhe end portions have corrugations 79, which are similar to thecorrugations of FGURES l-6, and are comprised of substantiaily straight,parallel, regular, and equally curved ridges 3) and valleys 81.

The respective sides 7i, 72 of the tiexor are partially nested in thegrooves 6e with the edges containing the abutments 77, 73 projectingoutwardly from the wiping element 55S. Each secondary yoke 5'7 and 5Shas a pair of claws S3 formed on the inner end portion 8d thereof and apair of claws formed on the outer shrouded end portion 8o thereof. illeclaws 83 and 35 on secondary yoke 57 engage around the edges of thereduced end portions 73 of the sides of the iiexor 5d, and the claws 3and 5s on the other secondary yoke engage around the other reduced endportions '.74 of the sides of the iiexor for hoiding the sides 721, 12of the iicxor Se seated in the blind grooves ed. The abutments d? at theends of the grooves en prevent the sides 7i, 72, of the iiexor fromsliding out of the ends of the rubber eiernent. The primary yoke 59 isattached to the yoices 57, Sis for holding the pressure-transmittingdevice bf2 assen bled on the tlexor 5e of the wiper biade 5l.

in the modiiied form or my invention, the corrugated rtion 'T9terminates just short of the inner and outer f fait, d5, respectively,of the secondary yolres v57, Sti. ne folies 57, are free to slide,within operative limits, on said flerror. The ridges fit? of thecorrugations 79 are adapted to engage the one wall of the grooves 66 andthe valleys Si of the corrugations are adapted to engage the other waliof the grooves o6 during normal conditions of use of the wiper blade andwiper assembly.

The modiiication of FEGURES 7-13 performs all of no novel functionsattributed to the preferred form shown in 1 6. The corrugations 79 canbe added to the liexor 5d at no extra cost to produce a blade thatreadily conforms to surfaces to be wiped.

Having thus described my invention, it is obvious that variousmodiications may be made in the same without departinr.7 from the spiritof the invention, and, therefore, i do not wish to be understood aslimiting myself to the exact form, construction, arrangement andcombination of parts herein shown and described.

E claim:

l. A iiexible backing member for a windshield wiper blade adapted towipe curved windshields, said member having at least two adiacentlongitudinal portions with a plurality of undulations extending aboveand below the plane of said backing member along axes lyingsubstantially perpendicular to the longitudinal axis of one of saidportions for reducing resistance to ening in one of said portions.

2. in a wiper blade for curved windshielda a resilient rubberliiieelongate wiping element, a resiliently and reversely exible elongatepressure-transmitting backing strip associated coactively therewith,said backing strip having a pluraiity of readily iiexible adjacent andintegral andasse portions substantially equal in width, at least one ofsaid portions having corrugations thereon, said corrugations comprisinga plurality of undulations extending above and below the plane ot saidbacking member along axes substantially perpendicular to thelongitudinal axis of said portion for substantially reducing theresistance of that portion to flexing relative to an adioining portionof the backing strip whereby to produce in the blade a greater inherentability to conform to a surface.

3. A flexible backing member for a windshield wiper blade adapted towipe curved windshields, said backing member being relatively ilexiblein a plane substantially normal to the windshield and relativelyinflexible in a plane transverse thereto, said backing member having atleast two longitudinal portions, one ot said portions having a greatereffective length than its over-all length and being thinner constantthroughout its length in the vertical dimension than at least one ofsaid other portions whereby to produce a greater degree of ilexibilityin said one portion than in the other.

4. A flexible backing member for supporting the wiping element of awindshield wiper blade for curved windshields, said backing member beingrelatively Ilexible in a plane substantially normal to the windshieldand relatively inilexible in a plane transverse thereto, said backingniember being manufactured from a material of a thickness required toprovide the minimum of flexibility desirable for at least onelongitudinal portion of said backing men ber, another longitudinalportion of said backing member being given additional etective lengthand less thickness by reversely corrugating said portion whereby toprovide less resistance to llexure in said last-named portion than insaid first-named portion.

5. ln a wiper blade for curved windshields, a resilient rubberlilreelongate wiping element, a resiliently and reversely flexible elongatepressure-transmitting backing strip associated coactively therewith,said backing strip being relatively flexible in a plane substantiallynormal to the windshield and relatively inilexible in a plane transversethereto, said backing strip being fabricated from material ofsubstantially uniform thickness and having a plurality of readilyflexible portions substantially equal in width, at least one o saidportions having transverse sinusoidal corrugations whereby to produce agreater degree of flexibility therein.

6. ln a wiper blade for curved windshields, a resilient rubberlikeelongate wiping element, a resiliently rlexible elongatepressure-transmitting backing strip associated coactively therewith,said backing strip being relatively ilexible in a plane substantiallynormal to the windshield and relatively inexible in a plane transversethereto, said backing strip having a plurality of adjacent readilyflexible portions substantially equal in width, at least one of saidportions having transverse continuous sinusoidal shaped corrugationswhereby to produce a greater degree of ilexibility therein.

7. ln a wiper blade for curved windshields, a resilient rubberlilteelongate wiping element, a resi .ently and reversely exiblepressure-transmitting bac ring strip associated coactively therewith,said backing strip being relatively exible in a plane substantiallynormal to the windshield and relatively iniiexible in a plane transversethereto,'said backing strip having a plurality of longitudinal portions,at least one of said portions having eorrugations transversely disposedrelative to the longitudinal axis of said blade whereby to produce insaid last-named portion a diiierent inherent resistance to flexure, saidcorrugations defined by adjacent continuous curved sections.

8. In a wiper blade for curved aviiidshields, a resilient rubberlikeelongate wi -ng element, a resiliently ilexible backing strip associatedcoactively therewith, said backing strip being iiexible in a planesubstanL ally normal to the windshield and being inflexible in a planetransverse thereto, said backing strip having a plurality oflongitudinal portions, a plurality of transverse corrugations formed inat least one of said portions whereby to reduce the resistance toflexing in said last-named portion, said corrugations being defined bycontinuous adjacent deformations `out of the plane of the backing strip.

9. Fexible backing means for a windshield wiper element which is adaptedto wipe a windshield having an irregular surface, said tlexible backingmeans being elonand adapted to be disposed generally coextensive withthe wiper element, said ilexible bacl'ing means having at least onelongitudinal portion provided with a. plurality of transversely disposedundulations extending above and below the plane of said longitudinalportion for reducing resistance to llexure in said longitudinal portion.

l0. ln a windshield wiper blade the combination of a resilient elongatewiping element having a wiping portion and a back portion spaced fromsaid wiping portion, a flexible elongate backing member engaging withsaid back portion of said lwiping element for coaction therewith, saidbacking member being exible in a plane substantially normal to thewindshield and relatively iniiexible in a plane transverse thereto, saidbacking member having at least one longitudinal portion corrugatedtransversely thereto, whereby to cause a difference in the inherentresistance to ilexure of said longitudinal portion of the ilexile memberto accommodate differing degrees of curvature of different areas of thesurface of a windshield to be wiped, and pressure-distributing structureapplying pressure to said backing member at longitudinally spacedapartportions thereof to distribute pressure of a windshield wiper arm to theblade, said corrugations being of continuous sinusoidal shape.

ll. ln a wiper assembly comprising a pressure-distributing deviceoperatively connected with a wiping blade comprising resilient elongatelexor means having end portions and an intermediate portion adapted tocooperate with said blade, said ilexor means being relatively flexiblein a plane substantially normal to the windshield and being relativelyinflexible in a plane transverse thereto, transverse sinusoidaloorrugations formed in at least one end portion thereof, said endportions of the iiexor means being operatively connected at spacedpoints to said pressure-distributing device to receive pressuretherefrom.

l2. A windshield wiper assembly comprising a pressuretransi-.ittingmember operatively connected with a wiper blade, said wiper blade havinga resilient elongate wiping element with a wiping portion and a backportion, ilexible elongate backing means for said wiping element forcoaction therewith, said backing means being relatively ilexible in aplane substantially normal to a windshield to be wiped. and beingrelatively inflexible in a plane transverse thereto, transversecorrugations formed in at least one end portion of said backing means,said transverse corrugations comprising a plurality ot adjacent curvedmeans formed out ot the pla. e or said backing member along aries lyingsubstantially perpendicular to the longitudinal axis of said backingmeans whereby said one end portion of the backing means is more freelyllexible than the rest o the backing means in said plane substantiallynormal to the windshield.

i3. A windshield wiper assembly comprising a pressuretransmitting memberoperatively connected with a wiper blade, said wiper blade having aresilient elongate wiping element with a wiping portion and a backportion, flexible elongate backing means for said wiping element forcoaction therewith, said backing means being relatively ilexible in aplane substantially normal to a windshield to be wiped. and beingelatively inflexible in a plane transverse thereto, transversecorrugations formed in at least one end portieri of said backing means,said corrugations comprising a plurality of undulations extending aboveand below the plane ot said backing me. .ber, said corrugations eachhaving an axis lying substantially perpendicular to the longitudinalaxis of said backing means whereby said one end portion of the backingmeans is more freely exbe than the rast of the backing means in saidplane Suosanaly normal is the Windshield.

UNlTED STATES 1% TENTS ,589,3 Cason Mar. 18, 1952 2,6GS,2 5 Ecl-m51 Aug.26, 1952 2,664,535 Qsei 5, 1954 2,772,436 Debel Dec. 4, 1956 2,782,445yKrohm Feb. 26, 1957 2,314,521 Wallis Dec. 3, 1957 2,871,495 Oishei eta1. Feb. 3, 1959 FOREEGN PATENTS 744,398 Great Britain Feb. 8, 1956'785,865 Great Briain Nov. 6, 1957 OTHER REFERENCES Germany, 517,81411/63C, Dec. 2Q, 1956.

1. A FLEXIBLE BACKING MEMBER FOR A WINDSHIELD WIPER BLADE ADAPTED TOWIPE CURVED WINDSHIELDS, SAID MEMBER HAVING AT LEAST TWO ADJACENTLONGITUDINAL PORTIONS WITH A PLURALITY OF UNDULATIONS EXTENDING ABOVEAND BELOW THE PLANE OF SAID BACKING MEMBER ALONG AXES LYINGSUBSTANTIALLY PERPENDICULAR TO THE LONGITUDINAL AXIS OF ONE OF SAIDPORTIONS FOR REDUCING RESISTANCE TO FLEXING IN ONE OF SAID PORTIONS.